So, after murdering both BG1EE and BG2EE and scrapping the whole thing and installing from scratch, this time making sure to chose correct language - it worked and now everything is in "proper" english.
Thanks!
I installed in the following order:
EET
IWD_1_EET
IWD_2_EET
subrace
bp-bgt-worldmap
icewind_eet
EET_end
It seems that for some campaigns (BG1 and Tutorial) EET pulled from pl_pl language files instead of en_us.
I made sure to select "english" every time, and that all games were set to English before the installation started.
How do I fix this?